Ok I have this item, I forget what it is called but it says that it requires a generator. And what are those focus things, it says shield strength and stuff like that, but no shield ever comes up. And I was looking at some craftable things as an artifice, and it says you can craft generators. Please explain all this, Im a noob :D
A Focus is an offhand 'weapon' for force users, it provides the same stats as a second lightsaber would for classes that aren't designed to dual wield.
A Generator serves the same purpose for tech users. The difference is that a focus has 'force power' as an attribute while a generator has 'tech power', they affect different things. To keep force users from using tech items or vice versa they have different weapon types.
A shield is for tanks, it allows them to block incoming attacks, but has less force power or tech power as a trade off.
If you're a damage dealer or a healer you'll want to use a generator or focus, depending if you use tech or force. If you're a tank you'll want to use a shield that has the appropriate stats for your class.